The added abdominal weight attending mid to late pregnancy, obesity, ascites, and various other conditions can produce significant lumbar back strain. In some cases a standard lumbar brace can provide significant assistance to the wearer, but in other cases (such as pregnancy) the ordinary lumbar braces are much too compressive on the peritoneum.
U.S. Pat. No. 5,094,648 to Turner (March 1992) shows one type of pregnancy support, in which a fabric encircles the torso, but remains open about the abdominal region so as not to compress the abdomen. This and all other referenced patents and applications are incorporated herein by reference in their entirety. While providing some measure of back support, devices such as that disclosed in the '648 patent do little or nothing to support the abdomen, or transfer abdominal weight onto the hips.
U.S. Pat. No. 6,071,175 to Loren Working (Jun. 6, 2000) teaches a supports designed specifically for pregnant women. That support provides a continuous carrier about the wearer's lower torso, with a front portion that is shorter (from bottom to top) than the sides and back, so that the front portion supports the extended lower abdomen substantially from below the extended abdomen. This arrangement provides needed support without excessive compression of the abdomen. The '175 patent also teaches a removable apron band that is said to facilitate installation and proper positioning of the front (natal support) portion.
Unfortunately, supports according to the '175 patent are not readily adjustable. One problem is that the back and side portions of the support are fixedly coupled to the front portion. Whether in pregnancy or other conditions, abdominal distension may occur high or low relative to the lumbar spine, and the positioning and extent of the distension commonly varies over time. The result is that proper fitting of the back and side portions of the support is often inconsistent with proper fitting of the front portion, and visa versa. It is possible to resolve that problem by producing a large number of different sizes, but that solution adds considerably to the manufacturing and stocking costs, as well as requiring a wearer to purchase multiple supports.
U.S. Pat. No. 5,060,639 to Marcus (October 1991) teaches a torso support comprising a back pad, side pads, and upper and lower front straps. The '639 device is advantageous in that the front straps are positioned above and below the most fully distended portion of the abdomen, but still cannot be positioned independently of the positioning of the back and side pads.
U.S. Pat. No. 4,952,192 to Burke (August 1990) provides a support undergarment with an abdominal support sling that connects to a dorsal panel. The nature of the connection is such that the sling could pivot to some extent, and therefore be positioned somewhat higher or lower on the abdomen as needed. Unfortunately, the mechanics is such that the weight carried by the sling passes through the pivot, so that the weight may well be improperly carried in all but the default position.
U.S. Pat. No. 4,557,268 to Maddux et al. (December 1985) provides front and back belts that connect at hook and loop type fasteners at the sides of the wearer. The connection in this instance provides some measure of independence in positioning between the front and back belts. There is an additional problem here with respect to use of the belts. The contemplated belts are substantially the same thickness across their entire lengths. If they are narrow enough to connect conveniently at the sides, then the belts are probably too narrow to comfortably support much abdominal weight. If they are wide enough to comfortably support additional considerable abdominal weight, then they would be cumbersome across the back, and in their connections to one another.
U.S. Pat. No. 4,108,149 to Castiglia (August 1978) provides a tall partially encircling, substantially rigid back brace portion, and a front portion that attaches to hook and loop fasteners on the front ends of the back portion. This device could be manipulated to provide higher or lower support as needed, but the use of a single front piece greatly limits the possible combinations.
Thus, there is a continuing need for a lower torso support in which the abdominal support portion is independently positionable relative to the back portion.